# Billy Loo, MD, PhD · NPI 1720167711

Radiation Oncology Physician · Stanford, CA · NPI 1720167711

Billy Loo, MD, PhD (NPI 1720167711) is listed in the NPPES registry with the specialty Radiation Oncology Physician in Stanford, CA, phone (650) 736-7143, as of the registry file of Jun 8, 2026.

Profile: https://www.gale.care/providers/ca/stanford/billy-loo-md-phd-1720167711
Facts changed: 2026-10-23 · hash ce96057bbbeaf86e

## Facts

- Name: Billy Loo (NPPES registry, self-reported, 2026-06-08) {#name}
- Credential: MD, PhD (NPPES registry, self-reported, 2026-06-08) {#credential}
- Specialty: Radiation Oncology Physician (NPPES registry, self-reported, 2026-06-08) {#specialty}
- Registry stage: as-listed (NPPES registry, self-reported, 2026-06-08) {#registry-stage}
- NPI issued: 2006 (NPPES registry, listed, 2026-06-08) {#npi-issued}
- Practice type: not-sole-proprietor (NPPES registry, self-reported, 2026-06-08) {#practice-type}
- City: Stanford (NPPES registry, self-reported, 2026-06-08) {#city}
- State: CA (NPPES registry, self-reported, 2026-06-08) {#state}
- Phone: (650) 736-7143 (NPPES registry, self-reported, 2026-06-08) {#phone}
- New patients: yes (Cigna's directory, listed, 2026-10-18) {#new-patients}
- Video visits: both (CMS Medicare clinicians file, listed, 2026-10-02) {#video}
- Insurance: Listed: DHCS Medi-Cal plan network listing listed Billy Loo, MD, PhD (NPI 1720167711) for Alameda Alliance for Health Medi-Cal plans on Apr 21, 2026. The state file is old; Gale found no newer one. {#ins-alameda-medi-cal}
- Insurance: Listed: DHCS Medi-Cal plan network listing listed Billy Loo, MD, PhD (NPI 1720167711) for Anthem Blue Cross Medi-Cal on Apr 21, 2026. The state file is old; Gale found no newer one. {#ins-anthem-medi-cal}
- Insurance: Listed: Blue Shield of California's directory listed Billy Loo, MD, PhD (NPI 1720167711) for Blue Shield of California commercial plans on Oct 22, 2026. Gale checked 60 listings in this directory by hand on Oct 22, 2026; 23 were wrong, so confirm with the office. {#ins-bsc-commercial}
- Insurance: Listed: Blue Shield of California's directory listed Billy Loo, MD, PhD (NPI 1720167711) for Blue Shield of California individual and family plans on Oct 22, 2026. Gale checked 60 listings in this directory by hand on Oct 22, 2026; 23 were wrong, so confirm with the office. {#ins-bsc-marketplace}
- Insurance: Listed: Blue Shield of California's directory listed Billy Loo, MD, PhD (NPI 1720167711) for Blue Shield of California Medicare Advantage plans on Oct 22, 2026. Gale checked 60 listings in this directory by hand on Oct 22, 2026; 23 were wrong, so confirm with the office. {#ins-bsc-medicare-advantage}
- Insurance: Listed: DHCS Medi-Cal plan network listing listed Billy Loo, MD, PhD (NPI 1720167711) for Central California Alliance for Health Medi-Cal plans on Apr 21, 2026. The state file is old; Gale found no newer one. {#ins-ccah-medi-cal}
- Insurance: Listed: Cigna's directory listed Billy Loo, MD, PhD (NPI 1720167711) for Cigna / Evernorth commercial plans on Oct 18, 2026. Gale checked 51 listings in this directory by hand on Oct 22, 2026; 3 were wrong, so confirm with the office. {#ins-cigna-commercial}
- Insurance: Listed: DHCS Medi-Cal plan network listing listed Billy Loo, MD, PhD (NPI 1720167711) for Contra Costa Health Plan Medi-Cal plans on Apr 21, 2026. The state file is old; Gale found no newer one. {#ins-cchp-medi-cal}
- Insurance: Listed: Health Net's directory listed Billy Loo, MD, PhD (NPI 1720167711) for Health Net commercial plans on Oct 19, 2026. Gale checked 12 listings in this directory by hand on Oct 22, 2026; 6 were wrong, so confirm with the office. {#ins-healthnet-commercial}
- Insurance: Listed: DHCS Medi-Cal plan network listing listed Billy Loo, MD, PhD (NPI 1720167711) for Health Plan of San Mateo Medi-Cal plans on Apr 21, 2026. The state file is old; Gale found no newer one. {#ins-hpsm-medi-cal}
- Insurance: Listed: DHCS Medi-Cal fee-for-service enrolment file listed Billy Loo, MD, PhD (NPI 1720167711) for Medi-Cal fee-for-service on Oct 19, 2026. {#ins-medi-cal-ffs-medi-cal}
- Insurance: Listed: CMS Medicare clinicians file listed Billy Loo, MD, PhD (NPI 1720167711) for Original Medicare on Oct 2, 2026. Gale checked 23 listings in this file by hand on Oct 22, 2026; none were wrong. {#ins-medicare-medicare}
- Insurance: Listed: UnitedHealthcare's directory listed Billy Loo, MD, PhD (NPI 1720167711) for UnitedHealthcare commercial plans on Oct 23, 2026. Gale checked 12 listings in this directory by hand on Oct 22, 2026; 6 were wrong, so confirm with the office. {#ins-uhc-commercial}
- Insurance: Listed: UnitedHealthcare's directory listed Billy Loo, MD, PhD (NPI 1720167711) for UnitedHealthcare Medicare Advantage plans on Oct 23, 2026. Gale checked 12 listings in this directory by hand on Oct 22, 2026; 6 were wrong, so confirm with the office. {#ins-uhc-medicare-advantage}
- Insurance: Likely: Aetna's price file suggests Aetna pays Billy Loo, MD, PhD (NPI 1720167711) for commercial plans (file of Oct 5, 2026). That is a lead, not a directory listing. {#ins-aetna-commercial}
- Insurance: Likely: Anthem Blue Cross's price file suggests Anthem Blue Cross pays Billy Loo, MD, PhD (NPI 1720167711) for commercial plans (file of Oct 1, 2026). That is a lead, not a directory listing. {#ins-anthem-commercial}
- Insurance: Likely: Anthem Blue Cross's price file suggests Anthem Blue Cross pays Billy Loo, MD, PhD (NPI 1720167711) for individual and family plans (file of Oct 1, 2026). That is a lead, not a directory listing. {#ins-anthem-marketplace}
- Insurance: Likely: Anthem Blue Cross's price file suggests Anthem Blue Cross pays Billy Loo, MD, PhD (NPI 1720167711) for workers' compensation (file of Oct 1, 2026). That is a lead, not a directory listing. {#ins-anthem-workers-comp}
- Insurance: Not listed by AIDS Healthcare Foundation (PHP) Medi-Cal plans for Billy Loo, MD, PhD (NPI 1720167711) in AIDS Healthcare Foundation (PHP)'s directory, file of Sep 19, 2026. That is not a no. {#ins-ahf-medi-cal}
- Insurance: Not listed by AIDS Healthcare Foundation (PHP) Medicare Advantage plans for Billy Loo, MD, PhD (NPI 1720167711) in AIDS Healthcare Foundation (PHP)'s directory, file of Sep 15, 2026. That is not a no. {#ins-ahf-medicare-advantage}
- Insurance: Not listed by Blue Shield of California Promise Health Plan Medi-Cal plans for Billy Loo, MD, PhD (NPI 1720167711) in Blue Shield of California's directory, file of Oct 22, 2026. That is not a no. {#ins-bsc-medi-cal}
- Insurance: Not listed by CalOptima Health Medi-Cal plans for Billy Loo, MD, PhD (NPI 1720167711) in CalOptima Health's directory, file of Oct 11, 2026. That is not a no. {#ins-caloptima-medi-cal}
- Insurance: Not listed by CalViva Health Medi-Cal plans for Billy Loo, MD, PhD (NPI 1720167711) in Health Net's directory, file of Oct 21, 2026. That is not a no. {#ins-calviva-medi-cal}
- Insurance: Not listed by Gold Coast Health Plan Medi-Cal plans for Billy Loo, MD, PhD (NPI 1720167711) in Gold Coast Health Plan's directory, file of Oct 9, 2026. That is not a no. {#ins-goldcoast-medi-cal}
- Insurance: Not listed by Ambetter from Health Net individual and family plans for Billy Loo, MD, PhD (NPI 1720167711) in Health Net's directory, file of Oct 22, 2026. That is not a no. {#ins-healthnet-marketplace}
- Insurance: Not listed by Health Net Medi-Cal plans for Billy Loo, MD, PhD (NPI 1720167711) in Health Net's directory, file of Oct 22, 2026. That is not a no. {#ins-healthnet-medi-cal}
- Insurance: Not listed by Wellcare by Health Net Medicare Advantage plans for Billy Loo, MD, PhD (NPI 1720167711) in Health Net's directory, file of Oct 22, 2026. That is not a no. {#ins-healthnet-medicare-advantage}
- Insurance: Not listed by Health Plan of San Joaquin Medi-Cal plans for Billy Loo, MD, PhD (NPI 1720167711) in Health Plan of San Joaquin's directory, file of Oct 2, 2026. That is not a no. {#ins-hpsj-medi-cal}
- Insurance: Not listed by Humana Medicare Advantage plans for Billy Loo, MD, PhD (NPI 1720167711) in Humana's directory, file of Oct 23, 2026. That is not a no. {#ins-humana-medicare-advantage}
- Insurance: Not listed by Inland Empire Health Plan (IEHP) individual and family plans for Billy Loo, MD, PhD (NPI 1720167711) in Inland Empire Health Plan (IEHP)'s directory, file of Jul 27, 2026. That is not a no. {#ins-iehp-marketplace}
- Insurance: Not listed by Inland Empire Health Plan (IEHP) Medi-Cal plans for Billy Loo, MD, PhD (NPI 1720167711) in Inland Empire Health Plan (IEHP)'s directory, file of Jul 29, 2026. That is not a no. {#ins-iehp-medi-cal}
- Insurance: Not listed by Inland Empire Health Plan (IEHP) Medicare Advantage plans for Billy Loo, MD, PhD (NPI 1720167711) in Inland Empire Health Plan (IEHP)'s directory, file of Oct 16, 2026. That is not a no. {#ins-iehp-medicare-advantage}
- Insurance: Not listed by Kern Family Health Care Medi-Cal plans for Billy Loo, MD, PhD (NPI 1720167711) in Kern Family Health Care's directory, file of Oct 9, 2026. That is not a no. {#ins-kern-medi-cal}
- Insurance: Not listed by L.A. Care Health Plan Medi-Cal plans for Billy Loo, MD, PhD (NPI 1720167711) in L.A. Care Health Plan's directory, file of Oct 19, 2026. That is not a no. {#ins-lacare-medi-cal}
- Insurance: Not listed by Optum Behavioral Health Medicare Advantage plans for Billy Loo, MD, PhD (NPI 1720167711) in UnitedHealthcare's directory, file of Oct 23, 2026. That is not a no. {#ins-optum-medicare-advantage}
- Insurance: Not listed by Partnership HealthPlan of California Medi-Cal plans for Billy Loo, MD, PhD (NPI 1720167711) in Partnership HealthPlan of California's directory, file of Oct 16, 2026. That is not a no. {#ins-partnership-medi-cal}
- Insurance: Not listed by San Francisco Health Plan Medi-Cal plans for Billy Loo, MD, PhD (NPI 1720167711) in San Francisco Health Plan's directory, file of Oct 1, 2026. That is not a no. {#ins-sfhp-medi-cal}
- Insurance: Not listed by UnitedHealthcare individual and family plans for Billy Loo, MD, PhD (NPI 1720167711) in UnitedHealthcare's directory, file of Oct 23, 2026. That is not a no. {#ins-uhc-marketplace}
- Insurance: Not listed by UnitedHealthcare Medi-Cal plans for Billy Loo, MD, PhD (NPI 1720167711) in UnitedHealthcare's directory, file of Oct 23, 2026. That is not a no. {#ins-uhc-medi-cal}
- Insurance: Not listed by VA Community Care for Billy Loo, MD, PhD (NPI 1720167711) in UnitedHealthcare's directory, file of Oct 23, 2026. That is not a no. {#ins-va-va}

## Answers

- New patients (listed): Cigna's directory listed Billy Loo, MD, PhD (NPI 1720167711) as taking new patients on Oct 18, 2026.
- Insurance (listed): Listed for Billy Loo, MD, PhD (NPI 1720167711): Alameda Alliance for Health, Medi-Cal (Apr 21, 2026); Anthem Blue Cross Medi-Cal (Apr 21, 2026); Blue Shield of California, commercial (Oct 22, 2026); Blue Shield of California, individual and family (Oct 22, 2026); Blue Shield of California, Medicare Advantage (Oct 22, 2026); and 9 more on the page. Each listing names its source and date.
- First-visit cost (not on record): Gale has no record of what a first visit with Billy Loo, MD, PhD (NPI 1720167711) costs. Paying yourself? You can ask for a written Good Faith Estimate before the visit.
- Video visits (listed): CMS Medicare clinicians file listed Billy Loo, MD, PhD (NPI 1720167711) for video and in-person visits on Oct 2, 2026.
- Where (self-reported): Billy Loo, MD, PhD (NPI 1720167711) is listed in Stanford, CA by the NPPES registry, as of the registry file of Jun 8, 2026.
- Who they see (not on record): Gale has no record of who Billy Loo, MD, PhD (NPI 1720167711) sees. Ask the office.
- What they help with (not on record): Gale has no record of what Billy Loo, MD, PhD (NPI 1720167711) helps with beyond the registry specialty. Ask the office.
- Languages (not on record): Gale has no record of the languages Billy Loo, MD, PhD (NPI 1720167711) speaks. Ask the office.
- How to book (self-reported): Call (650) 736-7143, the practice phone the NPPES registry lists for Billy Loo, MD, PhD (NPI 1720167711) (Jun 8, 2026).
- Next opening (not on record): Gale has no record of the next opening for Billy Loo, MD, PhD (NPI 1720167711). Ask the office.

## Sources

- NPPES registry (CMS): file of 2026-06-08 · https://npiregistry.cms.hhs.gov/provider-view/1720167711
- Aetna's price file: file of 2026-10-05 · Gale checked 12 leads from this price file by hand on Oct 22, 2026; 3 were wrong, so confirm with the office.
- AIDS Healthcare Foundation (PHP)'s directory: file of 2026-09-19
- Anthem Blue Cross's price file: file of 2026-10-01 · Gale checked 11 leads from this price file by hand on Oct 22, 2026; 8 were wrong, so confirm with the office.
- Blue Shield of California's directory: file of 2026-10-22 · Gale checked 60 listings in this directory by hand on Oct 22, 2026; 23 were wrong, so confirm with the office.
- CalOptima Health's directory: file of 2026-10-11 · Gale checked 12 listings in this directory by hand on Oct 22, 2026; 4 were wrong, so confirm with the office.
- Cigna's directory: file of 2026-10-22 · Gale checked 51 listings in this directory by hand on Oct 22, 2026; 3 were wrong, so confirm with the office.
- CMS Medicare clinicians file: file of 2026-10-02 · Gale checked 23 listings in this file by hand on Oct 22, 2026; none were wrong.
- DHCS Medi-Cal fee-for-service enrolment file: file of 2026-10-19
- DHCS Medi-Cal plan network listing: file of 2026-04-21
- Gold Coast Health Plan's directory: file of 2026-10-09
- Health Net's directory: file of 2026-10-22 · Gale checked 12 listings in this directory by hand on Oct 22, 2026; 6 were wrong, so confirm with the office.
- Health Plan of San Joaquin's directory: file of 2026-10-02
- Humana's directory: file of 2026-10-23
- Inland Empire Health Plan (IEHP)'s directory: file of 2026-10-16 · Gale checked 12 listings in this directory by hand on Oct 22, 2026; 4 were wrong, so confirm with the office.
- Kern Family Health Care's directory: file of 2026-10-09
- L.A. Care Health Plan's directory: file of 2026-10-19 · Gale checked 12 listings in this directory by hand on Oct 22, 2026; 4 were wrong, so confirm with the office.
- Partnership HealthPlan of California's directory: file of 2026-10-16
- San Francisco Health Plan's directory: file of 2026-10-01
- UnitedHealthcare's directory: file of 2026-10-23 · Gale checked 12 listings in this directory by hand on Oct 22, 2026; 6 were wrong, so confirm with the office.

## About these facts

- Status words: How each fact is known. confirmed = Listed: a named directory, CMS file or state file lists it. inferred = Likely: a price file suggests it; a likely match is a lead, not a listing. self-reported: the clinician said it, to the NPPES registry or on Gale. not-listed: a source that lists every clinician it covers was read and does not list this one; that is not a no. unknown: no record; ask the office.
- Dates: The date the source gives this record (YYYY-MM-DD). It is not the date of the event the record describes: an opt-out states its own start and end dates in its sentence.
- Hash: Changes only when a fact changes, never on a re-check.

This provider is not affiliated with Gale. This listing is compiled from the NPPES public registry (CMS).
Terms: https://www.gale.care/agents#terms